Method of making the water-communicating mechanism

ABSTRACT

In a method of making a water-communicating mechanism, provided is a bushing device capable of improving of a tight-fitting structure in which a bushing is tightly pushed into a water-communicating hole. When the bushing is secured to the water-communicating hole, the bushing collar is tightly fit into the water-communicating hole as a result of the wedge-shaped effect exerted between the tapered surfaces of the bushing and the bushing collar. Since the tapered surface of the bushing and the bushing collar are tightly fit, it is possible to significantly improve a heat-conductive efficiency between the bushing and the bushing collar, and reducing procedures needed to exchange casings with a good usability.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 14/126,110 filed on Feb. 10, 2014, now allowed, and titled“BUSHING DEVICE, WATER-COMMUNICATING MECHANISM AND A METHOD OF MAKINGTHE WATER-COMMUNICATING MECHANISM,” which claims priority ofPCT/JP2012/065041 filed on Jun. 12, 2012, Japanese Application No.2012-115141 filed on May 19, 2012, and Japanese Application No.2011-133086 filed on Jun. 15, 2011, the disclosure of all are herebyincorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a method of making thewater-communicating mechanism in which an aqueous medium (coolant) issupplied to a water-communicating hole (cooling hole) which is formed ona device body or a metal die to cool the device body or the metal die.

In a first prior art reference (Japanese Laid-open Patent ApplicationNo. 2006-289382), disclosed is a metal die cooling structure and amethod of making the metal die cooling structure in which aheat-conductive layer is provided between a casing inserted into acooling hole and an inner wall of the cooling hole. The heat-conductivelayer is filled with a molten metal (referred to as a filler metalhereinafter) having a low melting temperature.

More specific, a soldering material (alloyed metal having a low meltingtemperature) is provided between an outer surface of the casing and aninner surface of the cooling hole so as to obviate an air clearancetherebetween. After the alloyed metal is cooled and solidified, thealloyed metal resultantly fixes the casing within the cooling hole(refer to paragraph [0012]).

In a second prior art reference (Japanese Laid-open Patent ApplicationNo. 09-29416), disclosed is a molten-metal cooling pin used for a metaldie in which an inner cylinder and an outer cylinder are provided in adouble cylinder structure within a molten-metal cooling portion of themetal die.

More particularly, the outer cylinder is made of a steel-alloyed tool,and the inner cylinder is made of a copper-based alloy or a stainlesssteel.

In this instance, the inner cylinder is press fit into the outercylinder through their inner and outer surfaces by means of ashrinkage-fit or cooling-fit procedure (refer to paragraph [0007]).

The second prior art reference also discloses a tight-fittingheat-conductive layer in which a molten metal is solidified after themolten metal is poured into the air clearance between the inner cylinderand the outer cylinder.

In general, since the metal die has a cavity into which the molten metal(e.g., molten aluminum) is poured, the metal die is subjected to athermal shock due to an abrupt temperature rise. On the other hand, themetal die is subjected to a quick temperature drop caused by anevaporation heat of a separable agent applied to the metal die beforeseparating a female die from a male die. This may cause numerous cracks(referred also to as “die cracks” hereinafter) appeared on the cavity ofthe metal die.

The cooling hole formed on the metal die collects a cooling medium(e.g., cooling water) which causes a rust appeared to erode the metaldie. The rust together with the thermal shock facilitates to furtherdevelop the die cracks. When the die cracks develop such a degree as tocommunicate with the cavity, products which are made by pouring themolten metal into the cavity deteriorate their quality to anunacceptable level.

In order to prevent the cracks from occurring on the cavity, the casingand the inner cylinder (equivalent to the internal lining) are providedas mentioned in the first and second prior art references.

In the first prior art reference in which the molten metal is pouredinto the cooling hole to improve the tight-fitting structure between thecasing and the cooling hole, it requires a heating procedure to heat themetal die at a temperature (e.g., 600° C.) more than the filler metalcan melt when the filler metal is taken out of the metal die uponexchanging the casings (refer to paragraph [0019]). Namely, it isnecessary to implement the procedure to melt and solidify a properamount of the filler metal so as to obviate the air clearance, therebymaking the procedure laborious and time-consuming (not user-friendly).

Upon implementing the maintenance of removing strains from the metaldie, there would be a risk at the time of heating the filler metal thatthe filler metal will be molten to release the tight-fitting structurebetween the casing and the cooling hole. When the casing tightly engagesagainst the inner wall of the cooling hole, there is a possibility ofdeveloping the die cracks and the casing being partly broken toresultantly lose the function of the internal lining.

The second prior art reference which is represented by the tight-fittingheat-conductive layer in the molten-metal cooling pin used for the metaldie, has the same problems as mentioned in the first prior artreference.

The second prior art reference discloses a simplified structure in whichthe inner cylinder (made by a copper-based alloy or stainless steel) ispress fit into the outer cylinder. Due to the spring-back phenomenonwhen press fitting the inner cylinder into the outer cylinder with anelastic deformation accompanied, there would be a possibility that theinner cylinder will not completely engage with the outer cylinder, whichcauses to reduce a heat-conductive efficiency between the two cylinders.This makes it difficult to favorably control the temperature of themetal die when cooling the metal die.

Therefore, the present invention has been made with the above drawbacksin mind, it is a main object of the invention to provide a bushingdevice, a method of making the water-communicating mechanism which arecapable of achieving a tight-fitting structure between a device body andan inner wall of a water-communicating hole with a simplified structure.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a method of makinga water-communicating mechanism in which a bushing is provided on adevice body to be in communication with a water-communicating hole, sothat an aqueous medium is supplied to the bushing. A semi-sphericalportion is provided at a bottom of the water-communicating hole, and thebushing is in the form of bottom-ended cylindrical body, and a leadingportion of the bushing has a semi-spherical portion corresponding to thesemi-spherical portion of the water-communicating hole. A leadingportion of the bushing has a semi-spherical portion in conformity withthe semi-spherical portion of the water-communicating hole.

A bushing collar is inserted into the water-communicating hole. An innersurface of the bushing collar is tapered, and a diametrical dimension ofthe bushing collar is identical to a diameter of the water-communicatinghole. The bushing collar is inserted into the bushing. The bushing hasan outer surface tapered in accordance with the inner surface of thebushing collar. The bushing is pushed into the water-communicating holeby a predetermined depth, and when the bushing is inserted into thewater-communicating hole, a tapered surface of the bushing engages withthe tapered surface of the bushing collar while guided by the taperedsurface of the bushing collar, so that the bushing pushes the bushingcollar tightly against an inner surface of the water-communicating hole.

According to other aspect of the invention, a water-communicating meansis provided after the end of the tightly pushing step so as tocontinuously supply an aqueous medium to the bushing, and awater-communicating step is further provided to form a communicationpassage by means of the water-communicating means.

The water-communicating step signifies a procedure of connecting a watersource (e.g., a faucet of waterworks) through the water-communicatingmeans. Alternatively, the water-communicating step signifies a procedureof flowing the heat-exchanged water to an exhaust basin so as to form awater flow passage (equivalent to a cooling circuit).

According other aspect of the invention, at least either one of a firstfilling step before the end of inserting the bushing collar, or a secondfilling step is provided before the end of inserting the bushing. Afirst deformable filler is inserted at the first filling step, and asecond deformable filler is inserted at the second filling step.

Such is the structure that the bushing is pushed into thewater-communicating hole by a predetermined depth so that the bushingcollar is spread to tightly fit against an inner wall of thewater-communicating hole. Due to the wedge-shaped effect of taperedsurface in which the bushing pushes to spread the bushing collar, thebushing collar is brought to interpose between the bushing and thewater-communicating hole with the bushing collar tightly engaged withthe inner wall of the water-communicating hole. The bushing collarserves as an internal lining, and the bushing collar positively isolatesthe bushing from the inner wall of the water-communicating hole.

With a combination structure in which the bushing makes its taperedsurface fit with the tapered surface of the bushing collar, it becomespossible to tightly engage the bushing with the inner wall of thewater-communicating hole through the bushing collar. This makes itpossible to control the temperature of the device body (e.g., metal die)without losing a high heat-conductive efficiency.

With a simplified mechanical structure in which the bushing makes itstapered surface fit with the tapered surface of the bushing collar, itmakes the structure more labor-saving and convenient to use at the timeof implementing the maintenance when exchanging the casings, compared tothe prior art counterpart in which the molten metal is poured into theair clearance appeared on the cooling hole and the runner cooling pin.

With the simplified mechanical structure in which the bushing makes thebushing collar tightly engage with the inner wall of thewater-communicating hole when inserting the bushing into thewater-communicating hole, it becomes possible to obviate the spring-backphenomenon to strengthen the tight-fitting structure, as opposed to theprior art counterpart in which the inner cylinder is press fit into theouter cylinder.

Because the bushing collar positively isolates the bushing from theinner wall of the water-communicating hole, it is possible to keep thebushing off the water-communicating hole, thereby preventing the aqueousmedium from seeping into the water-communicating hole even when the diecracks occur on the metal die.

Upon removably mounting the flange portion on the cylindrical body, itbecomes possible to insert the cylindrical body into thewater-communicating hole even if the flange portion is non-concentricwith the cylindrical body and the water-communicating hole. This makesit possible to quickly assemble the flange portion to the cylindricalbody and the water-communicating hole.

By obviating the need of concentrically aligning the cylindrical bodywith the cylindrical body and the water-communicating hole, and alsoobviating the need of using a welding jig to prevent the cylindricalbody from being unfavorably deformed, it is possible to readily reducethe bushing device into mass production.

By mounting the flange portion on the cylindrical body through thehermetic sealing means, it is possible to tightly engage the flangeportion with the cylindrical body, thereby positively preventing a waterleakage between the flange portion and the cylindrical body. Byattaching the hooking means on the open-ended portion of the cylindricalbody, it becomes possible to easily take the cylindrical body out of thewater-communicating hole by catching the hooking means with a specialtool.

By inserting the deformable filler into the air clearance between thebushing and the bushing collar, it render unnecessary to demand exactdimensional sizes for the bushing and the water-communicating hole,thereby making it easy to check and control the products.

By inserting the metallic paste such as, for example, the metallicfibers and zinc into the air clearance between the bushing and thebushing collar, it is possible to prevent the rust from occurring on thebushing and the bushing collar, while improving the heat-conductiveefficiency therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred forms of the present invention are illustrated in theaccompanying drawings in which:

FIG. 1 is a schematic view of a water-communicating mechanism accordingto an embodiment of the invention;

FIG. 2 is a longitudinal cross sectional view of a water-communicatinghole in the water-communicating mechanism;

FIG. 3 is a longitudinal cross sectional view of a bushing collar whichis inserted into the water-communicating hole;

FIG. 4 is a longitudinal cross sectional view of a bushing which isinserted into the bushing collar installed in the water-communicatinghole;

FIG. 5 is a longitudinal cross sectional view of a bushing secured tothe metal die by means of a lock nut;

FIG. 6 is a longitudinal cross sectional view of the bushing in whichthe lock nut is tightened by a predetermined amount of turns;

FIG. 7 is an elevational side view of a coupler pipe;

FIGS. 8-10 are longitudinal cross sectional views of a part of thebushing collar according to modification forms A-C of the invention;

FIGS. 11-17 are exploded cross sectional views of the bushing accordingto modification forms (D)-(I) of the invention;

FIG. 18 is a longitudinal cross sectional view of the filler insertedinto the water-communicating hole according to a modification form (K)of the invention;

FIG. 19 is a longitudinal cross sectional view of the filler which isinserted between the bushing and the bushing collar;

FIG. 20 is a plan view of a flange portion according to a modificationform (M) of the invention;

FIG. 21 is an elevational side view of the flange portion;

FIG. 22 is a longitudinal cross sectional view of the flange portionwhich is secured by means of the lock nut; and

FIG. 23 is a plan view of the bushing device which is mounted on anengine.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description of the depicted embodiments, the samereference numerals are used for features of the same type. Positions anddirections of the various members are used to correspond to right-leftsides, and up-down sides of the attached drawings throughout eachembodiment of the invention.

Referring to FIGS. 1 through 7 which shows a bushing device, awater-communicating mechanism and a method of making thewater-communicating mechanism, the bushing device serves as a coolingtype bushing device 10, and the water-communicating mechanism serves asa metal die cooling mechanism S according to an embodiment of theinvention.

A metal die 80 is incorporated into the metal die cooling mechanism, andcategorically covered by a device body as an item to be cooled. As shownin FIGS. 1 and 2, the metal die 80 has a cavity side 81A whichconfigures the item to be cast, and having a die side 81B placedopposite to the cavity side 81A to have a cooling hole 82 cylindricallyformed as a water-communicating hole.

At an upper end portion of the cooling hole 82, a female thread portion83 is circumferentially provided as clearly shown in FIG. 2. From thefemale thread portion 83 downward, the downward hole 82A isconsecutively provided. An inner diameter of the female thread portion83 is identical to an inner diameter D1 of the downward hole 82A. Thecooling hole 82 has a bottomed portion which is defined as asemi-spherical portion 82B.

As shown in FIG. 1, the metallic die cooling mechanism S has the coolingtype bushing device 10 and a lock nut 22, the latter of which positivelyplaces the bushing device 10 in position within the cooling hole 82. Acoupler pipe 24 is connected to the bushing device 10. The bushingdevice 10 together with the coupler pipe 24 partly forms a watercommunication passage (equivalent to a cooling circuit) whichcontinuously supplies and drains a coolant as an aqueous medium(water-communicating medium).

As shown in FIG. 4, the cooling type bushing device 10 is a combinationof a cooling type bushing collar 12 and a cooling type bushing 14. Thecooling type bushing collar 12 serves as a bushing collar which can bemerely referred to as a collar hereinafter. The collar 12 and thebushing 14 are configured in accordance with contours of the coolinghole 82. The collar 12 is cut along a longitudinal direction to bedivided into two symmetrical parts as shown at phantom lines in FIG. 2.

The collar 12 is cut in a manner to divide a maximum diameter(equivalent to a diametrical portion) of the collar 12 into a pair ofcollar pieces 12A, 12B cut along the longitudinal direction.

When the collar 12 is inserted in the cooling hole 82, a gap distance T1appears between longitudinal sides of the collar pieces 12A, 12B asshown at solid lines in FIG. 3. For this reason, each of the collarpieces 12A, 12B is shaven at the diametrical portion by half of the gapdistance T1 along their longitudinal sides.

The collar 12 is preferably made by pressing a metallic material suchas, for example, copper and aluminum which are higher in bothheat-conductivity and ductility compared to a ferrous steel metal. Bymaking the identical collar pieces 12A, 12B by means of a pressingprocedure, it is possible to manufacture the collar 12 with a lowercost.

After the collar 12 and the cooling type bushing 14 are each insertedinto the cooling hole 82, the collar 12 forms a cylindricalconfiguration having a bottomed portion which aligns along an axial lineP of the cooling hole 82 as shown at dot-dash lines in FIG. 2. A leadingportion of the collar 12 is configured in conformity with thesemi-spherical portion 82B of the cooling hole 82.

Namely, a leading end of the collar 12 forms a semi-spherical endportion 12C as shown in FIG. 4. The collar 12 has a length L1 which issomewhat smaller than a total length of the downward hole 82A and thesemi-spherical portion 82B as shown in FIG. 3.

A diametrical dimension of the collar 12 is arranged to be identical tothe inner diameter D1 of the downward hole 82A when the cooling typebushing 14 is secured to the cooling hole 82 as shown in FIG. 6.

As shown at the phantom lines in FIG. 2, the collar 12 has an outersurface aligned along the axial line P. The collar 12 is arranged tobring the outer surface into tight-fitting engagement with an innersurface of the cooling hole 82. Instead of the word of tight-fittingengagement, the word of engagement is used as the same meaninghereinafter unless particularly specified.

In the meanwhile, as shown in FIG. 4, an inner surface of the collar 12forms a tapered surface 12D which slants against the axial line P. Thecollar 12 has a thickness which progressively increases as approachingthe semi-spherical end portion 12C from an insert opening 13 whichserves as an open end of the collar 12. For this reason, the taperedsurface 12D inclines against the axial line P from the insert opening 13to the semi-spherical end portion 12C. This means that the collar 12 hasthe inner surface configured to be tapered off toward the semi-sphericalend portion 12C. By way of illustration, the collar 12 is bored so thatthe tapered surface 12D has a gradient by a rate of 1/200.

As shown in FIG. 4, the cooling type bushing 14 has a bottom-endedcylindrical body 16 and a flange portion 18, the latter of which issecured (fixedly attached) to an open end 17 of the cylindrical body 16by means of welding procedure (e.g., soldering means). The cylindricalbody 16 serves as an internal lining of the water-communicatingmechanism.

As shown in FIG. 5, the flange portion 18 has an insert portion 19 andwhich is to be in communication with the open end 17 of the cylindricalbody 16. The flange portion 18 also has a circumferential portion,around which a male thread portion 20 is provided to be diametricallygreater than the insert portion 19. The flange portion 18 makes its malethread portion 20 tightened into the female thread portion 83 of thecooling hole 82.

It is to be noted that the outer diameter of the insert portion 19 issomewhat smaller than an inner diameter of the open end 17, so that theflange portion 18 can be inserted into the cylindrical body 16.

The flange portion 18 has a hexagonal wrench hole 18A, to which theAllen wrench (a.k.a. a hexagonal wrench, but not shown) is applied. Aninner hole 18A of the wrench lies in registration with the male threadportion 20. Under the wrench hole 18A, the flange portion 18 has afemale thread portion 18B to be in communication with the wrench hole18A. The female thread portion 18B is adapted to mesh with a male threadportion 34A which is provided on an outer surface of the coupler pipe 24as shown in FIG. 1.

It is noted that a welded portion in which the flange portion 18 isbonded to the cylindrical body 16 is located at an outer surface of thecylindrical body 16 in registration with the insert portion 19.

The cylindrical body 16 has a straight portion 16A, a tapered surface16B and a semi-spherical bottom 16C as shown in FIG. 5. The straightportion 16A which secures the flange portion 18, diametrically extendssubstantially by a length L2 from the open end 17 of the cylindricalbody 16 as shown in dot-dash lines in FIG. 5.

The tapered surface 16B is pushed to spread the collar pieces 12A, 12Bagainst an inner surface of the cooling hole 82. The semi-sphericalbottom 16C is to be in registration with the semi-spherical end portion12C of the collar 12. The cylindrical body 16 is integrally formed by ahigh-tension steel metal sheet such as, for example, a mild steel metalby means of the pressing procedure.

It is noted that the cylindrical body 16 may be formed by means of aboring procedure or swaging procedure, in lieu of the pressingprocedure.

The tapered surface 16B formed at an inner surface of the cylindricalbody 16, is tapered away in accordance with the tapered surface 12D ofthe collar 12 as observed by dot-dash lines Y which extends downwardfrom the straight portion 16A in FIG. 4. The tapered surface 16B rendersits inner diameter somewhat greater that an inner diameter of thetapered surface 12D of the collar 12.

This is because the tapered surface 12B is pushed to spread to bebrought into tight-fitting engagement with an inner wall (i.e., innersurface) of the cooling hole 82 upon inserting the cooling type bushing14 into the collar 12.

As shown in FIG. 6, a lock nut 22 is provided to mesh with the femalethread portion 83 of the cooling hole 82, so as to prevent the malethread portion 20 from being inadvertently loosened. The lock nut 22 hasa hexagonal wrench hole 22A formed similar to the wrench hole 18A of theflange portion 18.

For this reason, it is possible to concurrently secure the lock nut 22and the cooling type bushing 14 to the cylindrical body 16 by puttingthe wrench into the two holes 18A, 22A at the same time.

As shown in FIG. 7, the coupler pipe 24 serves as a water-communicatingmeans, and having a supply connector 28 which continuously supplies acoolant (e.g., aqueous medium, water) to the cooling type bushing 14.Connected to the supply connector 28 is a supply pipe 30.

A drainage connector 32 is to guide the heat-exchanged drain water to anexhaust basin (not shown). Connected to the drainage connector 32 is ashooting pipe 34. To the supply connector 28, a water-communicating pipe(not shown) is connected which comes from a water source (e.g., faucetof waterworks). The coupler pipe 24 extends the supply pipe 30 near asemi-spherical bottom portion 16M of the cylindrical body 16 as shown inFIG. 1.

Into the wrench holes 18A, 22A, a columnar support pipe 26 is insertedto be held upright as shown in FIG. 1. The shooting pipe 34 which islocated under the support pipe 26, is diameter-reduced more than thesupport pipe 26.

To an outer surface of the shooting pipe 34, a male thread portion 34Ais formed. The support pipe 26 is formed into a circular cylinder, sothat the support pipe 26 is inserted into and extended through thewrench holes 18A, 22A.

A method of making the metal die cooling mechanism S is described as amethod of assembling the metal die cooling mechanism S.

At a collar-insert step, the collar 12 is inserted into the cooling hole82. At a bushing-insert step, the cooling type bushing 14 is insertedinto the collar 12 placed within the cooling hole 82.

At a tight-fitting step (tightly fitting step), the cooling type bushing14 is pushed further into the cooling hole 82 to assemble the coolingtype bushing device 10. After assembling the cooling type bushing device10, the coupler pipe 24 is installed to the cooling type bushing device10 at a water-communicating step, so as to finish the assemble of themetal die cooling mechanism S.

At the collar insert step as shown at the phantom lines in FIG. 3, thecollar 12 is inserted into the cooling hole 82 with the collar pieces12A, 12B joined together, so as to make the collar pieces 12A, 12Bengaged with the inner wall of the cooling hole 82.

According to the embodiment of the invention, the collar pieces 12A, 12Bare formed by dividing the collar 12 into two parts, and the collarpieces 12A, 12B are shaven at the longitudinal sides. This makes theouter diameter of the joined pieces 12A, 12B smaller than the innerdiameter of the cooling hole 82, thereby making it possible to readilyinsert the collar 12 into and take the collar 12 out of the cooling hole82. This also prevents the inner wall of the cooling hole 82 from beingdamaged when inserting the collar 12 into and take the collar 12 out ofthe cooling hole 82.

At the bushing insert step as shown in FIG. 4, the cooling type bushing14 is placed at the insert opening 13 of the collar 12, so as to tightenthe male thread portion 20 around the female thread portion 83 with theuse of the Allen wrench (not shown).

In this situation, the lock nut 22 is tightened to push the cooling typebushing 14 until the lock nut 22 makes its head surface in flush withthe die surface 81B of the metal die 80 as shown in FIG. 5.

At the time when the lock nut 22 occupies the flush position, aclearance appears between an apex of the semi-spherical bottom 16C andan innermost concave portion of the semi-spherical end portion 12C asdesignated at a predetermined distance L3 in FIG. 5.

At the tight-fitting step as shown in FIG. 6, the cooling type bushing14 is further inserted by the distance L3, the lock nut 22 sinks by thedistance L3 under the die surface 81B. This makes the collar 12 (collarpieces 12A, 12B) spread so as to tightly engage with the inner wall(i.e., circumferential wall) of the cooling hole 82.

Namely, the cooling type bushing 14 pushes the collar 12 deeper againstthe inner wall of the cooling hole 82, while at the same time, guidingthe tapered surface 16B along the tapered surface 12D of the collar 12as shown in FIG. 4.

It is to be noted that in order to locate the cooling type bushing 14 inposition at a predetermined place as shown in FIG. 6, only the lock nut22 may be further tightened.

The collar 12 spread against the inner wall of the cooling hole 82 isdivided into the collar pieces 12A, 12B as shown in FIG. 3. The collar12 can be made of the copper metal which is higher in bothheat-conductivity and ductility compared to the ferrous steel metal.This makes the collar pieces 12A, 12B elastically deformable to obviatethe gap distance T1 to tightly join the collar pieces 12A, 12B together.

At the time of pouring the molten metal into the cavity of the metal die80, the metal die 80 is heated to rise its temperature. Because thecollar 12 thermally expands more than both the metal die 80 and thecooling type bushing 14, the collar pieces 12A, 12B elastically deformsto tightly join the collar pieces 12A, 12B together all the more.

With the result that the cooling type bushing 14 is pushed to spread thecollar 12 due to the wedge-shaped effect, this effect brings the collar12 into tight engagement with the inner wall of the cooling hole 82.This makes it possible to attain the tight-fitting structure between thebushing device 10 and the cooling hole 82 with a simplifiedconstruction.

With the collar 12 separating the cooling type bushing 14 from the innerwall of the cooling hole 82, it is possible for the collar 12 to preventthe cooling type bushing 14 from being directly in contact with theinner wall of the cooling hole 82. This makes it possible to avoid theaqueous medium from leaking off the cooling type bushing 14 to thecooling hole even when the die cracks occur on the metal die 80.

With a combined structure that the cooling type bushing 14 engages itstapered surface 16B with the tapered surface 12D of the collar 12, itbecomes possible to tightly engage the bushing device 10 with the innerwall of the cooling hole. This makes it possible to achieve a highheat-conductive efficiency therebetween, which is quite favorable whencontrolling the temperature of the metal die 80.

With the tight-fitting structure simplified between the bushing device10 and the cooling hole 82, it becomes possible to exchange the bushingdevices with less laborious and less time-consuming procedure comparedwith the prior art counterpart which interposes the molten metal betweenthe cooling hole and the molten-metal cooling pin.

Such is the structure that upon inserting the cooling type bushing 14into the cooling hole 82, the cooling type bushing 14 tightly engagesits tapered surface 12D against the inner wall of the cooling hole 82.This makes it possible to mitigate the spring-back phenomenon, therebymaintaining the tight-fitting structure for an extended period of time,as opposed to the prior art counterpart in which the inner cylinder ispress fit into the outer cylinder by means of the shrinkage-fit orcooling-fit procedure.

At the water-communicating step, the coupler pipe 24 is attached to thecooling type bushing 14 after the end of the tight-fitting procedure.

Namely, upon mounting the coupler pipe 24 on the cooling type bushing14, the supply pipe 30 is inserted into the cooling type bushing 14 asshown in FIG. 1. At the same time, the support pipe 26 is inserted intothe wrench holes 18A, 22A of the lock nut 22. Thereafter, the couplerpipe 24 brings its male thread portion 34A to mesh with the femalethread portion 18B of the flange portion 18, thereby concurrentlypreventing the aqueous medium from leaking off the support pipe 26.

In order to complete the water-communicating conduit, the supplyconnector 28 is attached to the spigot of the waterworks (not shown)through a communication pipe (not shown), and the drainage connector 32is led to a catchment basin through a communication pipe (not shown).

The water tapped from the waterworks is continuously supplied to thecylindrical body 16 of the cooling type bushing 14 through the supplyconnector 28 and the supply pipe 30, and drained to the catchment basinthrough the water pipe 34 and the drainage connector 32 as shown at anarrow in FIG. 1.

During the process in which the water is supplied as the aqueous mediumto the cooling type bushing 14, the water cools the metal die 80 throughthe cooling type bushing 14 when the molten-metal is poured into thecavity. The water heat-exchanged with the die metal is drained outsidethrough the water pipe 34.

As shown in FIGS. 8-10, it is to be noted that the collar 12 may beintegrally formed in one piece, in lieu of dividing it into two collarpieces 12A, 12B.

In a first modification form (A) depicted in FIG. 8, a notched portion38 is formed along the axial direction of the collar 12. The notchedportion 38 extends from the insert opening 13 to the proximity of theapex of the semi-spherical end portion 12C.

The apex of the semi-spherical end portion 12C may be formed into athickness-reduced configuration as designated by a thickness-reducedconnection 40 in FIG. 8. The thickness-reduced connection 40 is smallerin thickness by ⅓ than the semi-spherical end portion 12C.

Upon inserting the collar 12 into the cooling hole 82, the collar 12flexes its basal portion, thereby making it readily to insert the collar12 into and take the collar 12 out of the cooling hole 82. Theintegrally formed collar 12 prevents the collar 12 from beingadvertently lost, as opposed to the case in which the collar 12 isdivided into the collar pieces 12A, 12B.

In a second modification form (B) depicted in FIG. 9, thethickness-reduced connection 40 serves as a kerf 42 which is V-shaped incross section.

The kerf 42 has a depth dimension which is equivalent to one-third ofthe thickness measured at the apex of the semi-spherical end portion12C. In the second modification form B, the same advantages are achievedas accomplished in the first modification form (A).

In a third modification form (C) depicted in FIG. 10, the leading endportions (apexes) of the collar pieces 12A, 12B are bonded together toform a bonded connection 44 by means of such as, for example, thewelding procedure.

The bonded connection 44 has a thickness dimension which is equivalentto one-third of the thickness measured at the apex of the semi-sphericalend portion 12C. In the third modification form (C), the same advantagesare achieved as accomplished in the first modification form (A).

FIGS. 11 and 12 respectively show modification forms D and E representedby the cooling type bushing 14 in FIG. 5.

In the modification form (D) depicted in FIG. 11, an extension pipe 46is provided to connect between the flange portion 18 and the cylindricalbody 16.

This is because the extension pipe 46 is used when the cooling typebushing 14 is greater in length than the cooling hole 82 in FIG. 1. Theextension pipe 46 is fixedly connected to each of the flange portion 18and the cylindrical body 16 by means of the welding procedure. The otherstructure than the extension pipe 46 is the same as described in theembodiment of FIG. 4, describing the identical structure is omitted.

In the modification form (E) depicted in FIG. 12, a criss-cross groove48 is provided on an upper surface of the flange portion 18. Thecriss-cross groove 48 is used when screwing the cooling type bushing 14into the cooling hole 82.

In this instance, in lieu of the wrench hole 18A in FIG. 5, a circularhole may be provided which is in communication with the female threadportion 18B of the flange portion 18. The other structure than thecriss-cross groove 48 is the same as described in the embodiment of FIG.4, describing the identical structure is omitted.

FIGS. 13 and 14 respectively show modification forms (F) and (G)represented by the cooling type bushing 14 in FIG. 5. In both themodification forms (F) and (G), the flange portion 18 is removablemounted on the cylindrical body 16.

The modification forms (F) and (G) are employed to the case in which theflange portion 18 defies to concentrically align in the cylindrical body16 when the flange portion 18 is bonded to the cylindrical body 16 bymeans of the welding procedure (e.g., soldering or brazing procedure) asobserved in the preceding embodiment.

In the modification form (F) depicted in FIG. 13, an upper end of thecooling type bushing 14 has an outer flange 16D in perpendicular to theaxial direction integrally formed upon drawing the cooling type bushing14. The outer flange 16D is placed such as not to be an interference inthe female thread portion 83 of the cooling hole 82.

In the flange portion 18 of the insert portion 19, the insert portion 19determines its outer diameter somewhat greater than an inner diameter ofthe straight portion 16A of the cylindrical body 16.

Into an outer surface of the insert portion 19, an annular sealant 50 isinserted as a hermetic sealing means. The sealant 50 which is slightlygreater in axial length than the insert portion 19, is provided bymolding a synthetic resin by way of illustration.

The sealant 50 has an inner diameter which is slightly smaller than anouter diameter of the insert portion 19.

For this reason, the sealant 50 is fixedly installed on the flangeportion 18 to tightly fit against the insert portion 19 and the flangeportion 18.

Namely, the sealant 50 is fixedly pressed against the outer flange 16Dof the cylindrical body 16, while at the same time, a lower side of theinsert portion 19 comes in contact with the outer flange 16D. This makesit possible to air-tightly seal between the flange portion 18 and theouter flange 16D, thereby preventing the coolant (aqueous medium) fromleaking through therebetween.

With the flange portion 18 removably mounted on the cylindrical body 16,it is possible to insert the cooling type bushing 14 into the coolinghole 82 even when the flange portion 18 defies to concentrically alignin the cylindrical body 16. This also makes it possible to readilyassemble the flange portion 18 to the cylindrical body 16.

The above structure enables users to obviate the concentrically aligningprocedure against the cylindrical body 16, while at the same time,removing the need of handling a welding jig to prevent the cylindricalbody from being unfavorably deformed, it is possible to readily reducethe cooling type of bushing 14 into mass production with an improvedefficiency. The other structure than the removable-mounting componentsis the same as described in the embodiment of FIG. 5, describing theidentical structure is omitted.

It is further to be noted that the sealant 50 may be determined to besmaller in axial length than the insert portion 19, so that the insertportion 19 can be dimensionally determined to be insertable into aninner surface of the cylindrical body 16.

In the modification form (G) depicted in FIG. 14, the cooling type ofbushing 14 makes an O-ring 52 place around an outer surface of theinsert portion 19. On the outer surface of the insert portion 19, acircumferential groove is provided into which the O-ring 52 is interfit.The insert portion 19 together with the O-ring 52 is inserted into(i.e., connected to) the cylindrical body 16.

In this situation, it is to be noted that the outer flange 16D can beomitted from the cylindrical body 16. The other structure than theO-ring 52 and the groove is the same as described in the modificationform (F), describing the identical structure is omitted.

In the modification form (H) depicted in FIG. 15, the flange portion 18is removably mounted on the cylindrical body 16 by means of a screwcomponent provided as the hermetic sealing means.

As mentioned in the modification forms depicted in FIGS. 13 and 14, themodification form (H) makes it possible to insert the flange portion 18into the cylindrical body 16 even when the flange portion 18 does notconcentrically align with the cylindrical body 16.

In the modification form (H), a screw collar 54 is welded as areinforcement to an inner side of the straight portion 16A (open-endedportion 17) of the cylindrical body 16. The screw collar 54 is formedinto an annular configuration, and having an inner surface which isformed into a female thread portion 54A to serve as a hooking means.

On an outer surface of the insert portion 19, a male thread portion 18Cis provided which meshes with the female thread portion 54A, so as toresultantly secure the flange portion 18 to the cylindrical body 16through the screw collar 54 as shown in FIG. 16.

The screw collar 54 has an outer diameter determined to be slightlygreater than an inner diameter of the straight portion 16A. The screwcollar 54 press fits its outer surface circumferentially into an upperend portion of the straight portion 16A as shown at phantom lines inFIG. 15. The welding procedure is applied entirely to a press fittingarea between the screw collar 54 and the straight portion 16A.

With the screw collar 54 press fit into the cylindrical body 16, it ispossible to minimize the deformation caused by the thermal influence, towhich the cylindrical body 16 is subjected due to the welding procedure(fixing means).

Thereafter, the cylindrical body 16 is inserted into the cooling hole82, and then the flange portion 18 is secured to the screw collar 54 bymeshing the male thread portion 18C with the female thread portion 54A.

In this situation, a heat-resistant sealant (not shown) may be appliedto the male thread portion 18C or the female thread portion 54A to holdan air-tightness therebetween.

In the modification form (H), such is the structure that the flangeportion 18 is inserted into the cylindrical body 16 through the screwcollar 54. This makes it possible to omit the axially aligning procedurebetween the flange portion 18 and the cylindrical body 16, therebyenabling the users to improve an assembling efficiency when reduced tomass production.

Upon meshing the male thread portion 18C with the female thread portion54A, the Allen wrench (not shown) is applied to the hexagonal hole 18Aas observed in FIG. 16. The other structure than the screw collar 54 andthe male thread portion 18C is the same as described in the modificationforms (F) and (G), describing the identical structure is omitted.

It is to be noted that the flange portion 18 may be provisionally weldedto the cylindrical body 16.

In this instance, the flange portion 18 is welded at four locations atregular intervals (e.g., 90 degrees) to the outer surface of thecylindrical body 16, the locations of which correspond to the insertportion 19.

Even with the provisional welding procedure applied to the cylindricalbody 16, it is sufficient to fixedly secure the flange portion 18 to thecylindrical body 16, while minimizing the unfavorable deformation due tothe welding procedure. The screw collar 54 may be used to thecylindrical body 16 formed integral with the outer flange 16D.

FIG. 17 shows a modification form (I) of the cooling type bushing 14 inwhich the flange portion 18 is removably mounted on the cylindrical body16. A female thread portion 16E is directly formed on the inner surfaceof the straight portion 16A to serve as a part of the hermetic sealingmeans.

The insert portion 19 has an outer diameter corresponding to the femalethread portion 16E. The outer surface of the insert portion 19 has themale thread portion 18C (referred to FIG. 15) to serve as a part of thehermetic sealing means or the hooking means.

The flange portion 18 brings the male thread portion 18C to mesh withthe female thread portion 16E upon securing the flange portion 18 to thecylindrical body 16. In this situation, the heat-resistant sealant (notshown) may be applied to the male thread portion 18C or the femalethread portion 16E to hold the air-tightness therebetween. The sealant50 as observed in FIG. 13 may be used to a basal end of the insertportion 19.

In order to take the cylindrical body 16 out of the cooling hole 82, theflange portion 18 is first taken from the cylindrical body 16 byapplying the Allen wrench to the hexagonal hole 18A (refer to FIG. 15).Then, a special tool 90 (knock-release tool) is used to take thecylindrical body 16 out of the cooling hole 82. The special tool 90 hasa slidable weight which produces an impact when slid along a rail (notshown) to release an item (cylindrical body 16) to be taken out.

The special tool 90 has a male thread portion 90A meshed with the femalethread portion 16E. By sliding the weight, the impact enables the usersto readily release the cylindrical body 16 out of the cooling hole 82.

When the flange portion 18 is fixedly secured to the cylindrical body 16by means welding procedure as shown in FIG. 5, the special tool 90brings the male thread portion 90A to mesh with the female threadportion 18B, in order to take the flange portion 18 out of the coolinghole 82.

It is noted that any hook portion will be usable so long as it can becaught with a detachment tool. The other structure than the special tool90 is the same as described in the modification form (H), describing theidentical structure is omitted.

In a modification form (K) depicted in FIGS. 18 and 19, the filler isprovided entirely at a first clearance between the collar 12 and thecooling hole 82, or the filler is provided entirely at a secondclearance between the collar 12 and the cooling type bushing 14 as anair-bleeding action. This is to ameliorate the heat-conductiveefficiency between the collar 12 and the cooling hole 82, or between thecollar 12 and the cooling type bushing 14. By way of illustration, abundle of metallic fibers 60 available in market or a certain amount ofa metallic paste 62 is used as the filler.

The metallic fibers 60 (approx. 50 μm in diameter) are made from metalscombined with titanium, copper and brass. The metallic paste 62 has agranulated zinc (approx. 96% of a total) and a non-combustible epoxyresin as a rust-resistant material. Zinc has a tendency to ionize andoxidize in preference to iron. An oxide film formed on zinc prevents therust from appearing thereon. Zinc also has a heat-conductivity higherthan that of iron (equivalent to that of copper), and less soluble thanaluminum. For this reason, zinc is well-suited to fill the clearanceswith the filler. The filler categorically includes a metallic powder(e.g., granulated copper).

In the modification form (K) depicted in FIG. 18, the first clearance isfilled with the metallic fibers 60 or the metallic paste 62 between thecooling hole 82 and the collar 12. Then, the second clearance is filledwith the metallic fibers 60 or the metallic paste 62 between the coolingtype bushing 14 and the collar 12. The metallic fibers 60 or themetallic paste 62 deforms in accordance with the shape of the clearancesto fully load the clearances because the metallic fibers 60 plasticallydisplaces and the metallic paste 62 evenly flows. In case of themetallic paste 62, the paste 62 may be molded by means of a sinteringprocedure.

An amount of the metallic fibers 60 and an amount of the metallic paste62 may be altered under different circumstances. The metallic fibers 60and the metallic paste 62 may be employed in combination or singularity.The filler may be applied only to one of the first clearance and thesecond clearance. Alternatively, the filler may be applied both of thefirst clearance and the second clearance.

The filler is deformable that the filler loads the clearances with themetallic fibers 60 (metallic paste 62) in accordance with the shape ofthe clearances. This allows a latitude in precision to the cooling typebushing device 10 and the cooling hole 82, thereby rendering it easy tomaintain and control the products. The filler makes it possible toimprove the heat-conductive efficiency while preventing the rust fromappearing thereon.

In a modification form (M) depicted in FIGS. 20 and 21, the flangeportion 18 and the lock nut 22 are deformed to prevent the flangeportion 18 from being inadvertently loosened. The flange portion 18forms a hook head 21 on the upper surface of the male thread portion 20.The hook head 21 has straight portions 21A and tapered portions 21B, thelatter of which are consecutively formed from a peripheral portion ofthe straight portions 21A. The hook head 21 is determined to bediametrically smaller than the male thread portion 20.

The hook head 21 is linearly notched at both sides to form a pair of thestraight portions 21A, so that the straight portions 21A can be caughtby a spanner (tightening tool). The tapered portions 21B positionbetween the opposed straight portions 21A, and extend from an outerperiphery of the hook head 21 toward the male thread portion 20, so asto form an arc-shaped configuration.

As shown at broken lines in FIG. 21, the flange portion 18 forms acircular hole 21C diametrically greater than the female thread portion18B, and designed to be in communication with the female thread portion18B. To the circular hole 21C, the support pipe 26 of the coupler pipe24 (referred to FIG. 5) is to be inserted.

As shown in FIG. 22, a lock nut 70 is provided to be diametricallyidentical to the male thread portion 20 of the flange portion 18. Thelock nut 70 has a wrench hole 70A to which the Allen wrench is applied,while at the same time, the wrench hole 70A is formed to guide thesupport pipe 26 to pass through.

The lock nut 70 has a lock surface 70C located to face the flangeportion 18. The lock surface 70C has an outer peripheral portion flaredto entirely engage with the tapered portion 21B so as to form a taperedsurface 70B.

With an outer side of the lock nut 70, a male thread portion 70D isprovided to mesh with the female thread portion 83 of the cooling hole82, as is the case with the male thread portion 20 of the flange portion18.

The lock nut 70 engages its lock surface 70C with the flange portion 18,and brings the tapered surface 70B into tight engagement with thetapered portions 21B of the hook head 21 when the lock nut 70 istightened.

In the modification form (M), the cooling type bushing 14 is firstinserted into the cooling hole 82. Then, the spanner is applied to thestraight portions 21A in order to turn the lock nut 70 to place thecooling type bushing 14 in position in the cooling hole 82.

With the use of the Allen wrench, the lock nut 70 presses the flangeportion 18 and resultantly brings its male thread portion 70D intoengagement with the female thread portion 83 of the cooling hole 82.

In the modification form (M), the double-nut action exerts between themale thread portion 20 and the male thread portion 70D, while thewedge-shaped effect works between the tapered portion 21B and thetapered surface 70B.

Due to the double-nut action and the wedge-shaped effect, it is possibleto further prevent the flange portion 18 (i.e., cooling type bushing 14)from being loosened.

The device body categorically includes the metal die (shown in thepreceding embodiment) and an engine.

In a three-cylinder type engine 86 depicted in FIG. 23, it is consideredto be structurally difficult to cool a central cylinder 87B among thethree cylinders 87A-87C. In order to overcome the difficulty, aplurality of the cooling type bushing devices may be convergentlylocated around the central cylinder 87B.

In this instance, water jackets 88 are placed at both sides to straddlethe cylinders 87A-87C. This enables the users to cool the cylinder 87Bnot only by the water jackets 88 but also by the plurality of thecooling type bushing devices. The water coolant may be circulated eitherthrough one-way or two-way path.

The device body also includes a central processing unit (CPU) of a supercomputer, a capacity of which is such as to require one floor of abuilding to accommodate. Namely, the cooling type bushing device 10 isapplicable to the central processing unit (CPU) which serves as thedevice body.

In the meanwhile, the cooling type bushing device 10 is also employednot only to cool the device body but also to pre-heat the device body.By way of example, a certain amount of hot water (e.g., 100° C.) may becirculated within the cooling type bushing device 10.

The metal die categorically includes a molten-metal cooling pin(equivalent to the prior art outer cylinder) which comes in directcontact with the molten metal.

The cooling pin has a cooling path and constitutes a part of the metaldie when used to the die-casting procedure. The cooling type bushingdevice 10 may be inserted into the cooling path of the cooling pin.

The metal die includes a molten-metal pouring device placed on astationary side of the metal die and a sub-flowing device placed on amovable side of the metal die. Namely, the bushing device may beinserted into a cooling passage provided on the metal die or thesub-flowing device.

In the molten-metal pouring device which is subjected to an abrupttemperature rise (thermal fluctuation), and the cooling hole 82 isair-tightly sealed with the cooling type bushing 14 by means of a lid,it is preferable to employ the cooling type bushing 14 in which thecylindrical body 16 and the flange portion 18 are integrally bonded bymeans of the welding procedure or the like.

It is to be noted that a gradient of the tapered surface 12D may bechanged to any desired degrees (e.g., 1/150) depending on usage. Thecollar 12 may be divided into a plurality of collar pieces (e.g., 3-4pieces) other than the two collar pieces 12A, 12B.

The cooling type bushing 14 may be completely mounted on the coolinghole 82 at any position in which the flange portion 18 meshes the malethread portion 20 with the female thread portion 83. At the same time,the provisional welding may be used to prevent the flange portion 18from being loosened. The water heat-exchanged at the cooling typebushing device 10 may be cooled down to reuse as a circulation system.

The collar 12 may be cast by means of the sintering procedure with thecopper powder (granulated copper) heated within a die. The flangeportion 18 may be formed integral with the cylindrical body 16 toproduce the cooling type bushing 14.

The tapered surface 12D of the collar 12 and the tapered surface 16B ofthe cylindrical body 16 may be formed straight. In this case, theclearances are loaded with the metallic fibers 60 or metallic paste 62.

Among the preceding embodiment and the modification forms A-K thus farmentioned, two or more examples may be combined.

While several illustrative embodiments of the invention have been shownand described, numerous variations and alternate embodiments will occurto those skilled in the art. Such variations and alternate embodimentsare contemplated, and can be made without departing from the spirit andscope of the invention as defined in the appended claims.

What is claimed is:
 1. A method of making a water-communicatingmechanism in which a bushing is provided on a device body to be incommunication with a water-communicating hole so that an aqueous mediumis supplied to said bushing, and a semi-spherical portion provided at abottom of said water-communicating hole, and said bushing being in theform of bottom-ended cylindrical body, and a leading portion of saidbushing having a semi-spherical portion corresponding to saidsemi-spherical portion of said water-communicating hole; said methodcomprising steps of; inserting a bushing collar into saidwater-communicating hole, an inner surface of said bushing collar beingtapered and a diametrical dimension of said bushing collar beingidentical to a diameter of said water-communicating hole; inserting saidbushing collar into said bushing, said bushing having an outer surfacetapered in accordance with said inner surface of said bushing collar, aleading portion of which has a semi-spherical portion in conformity withsaid semi-spherical portion of said water-communicating hole; tightlypushing said bushing into said water-communicating hole by apredetermined depth, and when said bushing is inserted into saidwater-communicating hole, a tapered surface of said bushing engages withsaid tapered surface of said bushing collar while guided by said taperedsurface of said bushing collar, so that said bushing pushes said bushingcollar tightly against an inner surface of said water-communicatinghole.
 2. The method of making a water-communicating mechanism accordingto claim 1, wherein a water-communicating means is provided after theend of said tightly pushing step so as to continuously supply saidaqueous medium to said bushing, and a water-communicating step isfurther provided to form a communication passage by means of saidwater-communicating means.
 3. The method of making a water-communicatingmechanism according to claim 1 or 2, wherein at least either one of afirst filling step provided before the end of inserting said bushingcollar, or a second filling step is provided before the end of insertingsaid bushing, a first deformable filler being inserted at said firstfilling step, and a second deformable filler is inserted at said secondfilling step.